The present invention is directed to a suction pump which resists clogging and is capable of effectively pumping liquid containing rocks and other solids with greater efficiency and reduced wear. The device is particularly suited for use in mining and similar applications requiring efficient, durable and inexpensive hand-operated pumps capable of withstanding the additional wear of pumping abrasive slurries or solutions containing solids while achieving sufficient suction to operate at productive volumes.
Suction pumps of the prior art, as shown, for example, in Hayward, U.S. Pat. No. 2,476,545 and Anderson U.S. Pat. No. 3,062,415, fail to disclose a flexible suction inducing element which relaxes or collapses during the return stroke of the handle so as to minimize the resistnace of the suction element to downward movement within a tubular housing containing rocks or other solids. Such devices, instead, employ valve controlled ports within the suction element to alternately open or close the desired passageway at each stroke. All such prior art devices are ineffective in reliably preventing clogging when pumping combinations of liquids and solids. Further, such prior art devices sustain considerable wear when used in such applications and frequently fail to provide the required suction to transport the heavier solids in such mixtures.